package day07;

import java.util.Random;

public class VerificationCode {
    public static void main(String[] args) {

        String code=generateVeriCode(20);
        System.out.println("您收到的验证码为："+code);
    }

    /*
    public static String generateVeriCode(int len){

        String code=" ";
        char[] chs={'a','b','c','0','1','2','3','4','5','6','7','8','9','0','d','e','f','g','h','i','j',
                'k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E',
                'F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
        Random ran=new Random();
        for(int i=1;i<=len;i++){
            int index=ran.nextInt(chs.length);
            code +=chs[index];//获取随机字符并拼接到code中
        }
        return code;
    }

     */

    public static String generateVeriCode(int len){
        String  code="";
        char[] chs={'a','b','c','0','1','2','3','4','5','6','7','8','9','0','d','e','f','g','h','i','j',
                'k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E',
                'F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
        Random ran=new Random();
        for(int i=1;i<=len;i++){
            int index= ran.nextInt(chs.length);
            code +=chs[index];
        }

        return code;
    }
}
